1. Field of the Invention
The present invention generally relates to geometric processing in graphics systems and more specifically to a system and method for perspective corrected tessellation using parameter space warping.
2. Description of the Related Art
Modern three-dimensional (3D) graphics systems are typically configured to generate one or more graphics images from one or more graphics scenes, with each graphics scene comprising one or more geometric models. The one or more graphics images are then displayed or stored for display later. Each geometric model may include geometric objects such as triangles, meshes, parametric patches, or other types of constructs useful in rendering a graphics scene. Certain geometric objects are tessellated into a mesh of smaller objects for rendering in finer geometric detail. Conventional tessellation is typically performed for a given geometric object in a parametric space with uniform world-space sampling.
In general, uniform world-space sampling produces uneven screen-space sampling, which appears as an uneven distribution of tessellation detail in a rendered image. When a geometric object is rendered in a perspective that produces severe foreshortening, the uniform world-space sampling produces severely uneven screen-space sampling, which appears as very dense tessellation at depth, and very sparse tessellation close to the viewer. Very dense tessellation can create unproductive workload for a 3D graphics system, while very sparse tessellation degrades overall image quality of the one or more graphics images.
Accordingly, what is needed in the art is a system and method for improving overall image quality of tessellated objects in a 3D graphics system.